The goals of this project are to identify and monitor the effects of cancer and its treatment on the neuropsychological development of children. A large cohort of children with leukemia and solid tumors have been followed through three years of treatment to assess the effects of central nervous system (CNS) treatment on children ' with leukemia. However, patients were followed for a relatively brief period, and brain tumor patients were excluded from the investigation. In contrast to children with tumors outside the CNS and whose disease and treatment are usually less 1 intensive, children with brain tumors show a high incidence of neuropsychological impairment severe enough to interfere with their attainment of long-term educational and occupational goals. The aims of this prospective study are to 1) extend our knowledge of longitudinal change in participants in the current prospective study to periods of 6-8 years post-diagnosis; 2) examine changes in neuropsychological performance of children with brain tumors across a three-year period beginning at diagnosis; 3) compare changes in performance of children with brain tumors with those of other cancer patients; and 4) identify characteristics of patients. diseases, and treatments that will contribute to the interpretation of neuropsychological findings. This study will extend the time line of the current study as well as generate a cross-validation sample of brain tumor and other types of cancer patients from whom comparable data will be obtained. To achieve the first objective, 100 surviving participants in the currently funded study will be followed for an additional three years to assess change over long- term post-therapy follow-up. To achieve Objectives 2 and 3, studies of 120 brain tumor patients and 120 other cancer patients will be conducted using a repeated measures design. Patterns of decline and growth will be assessed using a hierarchical linear modeling approach. All groups will be included in the analyses of Objective 4. To meet sample requirements for Objectives 2 and 3 and to enhance generalizability of findings, The University of Texas H. D. Anderson Cancer Center and Georgia State University/Emory have agreed to collaborate. Achievement of these aims will enhance our ability to identify risk factors associated with specific processing deficits among pediatric cancer patients and assess their implications for school achievements.